I hear you. It's not enough for people to simply say "I (don't) like it, so I (don't) buy it." They have to come up with sometimes asinine, overly complex rationalizations to make it seem like they're making the only logical choice. If you take care of them, then even cheap, leather shoes can last for a long time.

First, contact your friends to verify that their idea of "black tie" is what you have in mind. Some people use the words "formal" and "black tie" when they only mean "wear a suit."
Second, go from there.
EDIT:
Third, don't wear that vest. The double-lapel 3-piece is one of the worst-looking suits out there, but I see it quite a bit. I guess guys think that it makes them look more fancy. It makes them look like idiots...just my opinion though.

If you have a fit/muscular build, then a really slim polo works great for the summer. Old Navy slim fit polos are good IMO. Paying more than about $15 is a waste of money. ON polos can be found between $12 and $15. Some things aren't worth paying premium prices for.